Biopsy using radiofrequency surgery

A skin biopsy should not only be performed when one suspects malignancy, but as a routine for many of the common skin lesions surgically removed in practice. Simultaneously, a biopsy is done many times to diagnose a skin disease when eluding diagnosis or when the given treatment fails to give expected results.

A skin biopsy has been commonly done using a scalpel or curette or punches of various sizes. As noted earlier, techniques of electrocautery, cryotherapy, and lasers are not suitable for biopsy, though cryotherapy may be used in some cases.

Radiofrequency surgery serves as a good option for doing a skin biopsy. Since the time I started this technique, I noticed that lesions removed had the skin structure very nicely preserved, as the cut is very fine. After observing this, I thought of using this for excision biopsy, which succeeded. The histopathology report remarked that the tissue architecture was well preserved except for some thermal changes at margins.

It has been proved in various scientific studies that radiofrequency surgery has one of the thinnest cuts (10–20 microns).1,2

Gradually, as I developed more experience using radiofrequency surgery in practice, I stopped using punch for biopsy. Using punch for biopsy only became cumbersome, so I omitted it from practice.

Using radiofrequency surgery I could use the same tool for treatment as well as diagnosis. I have since then used it for all cases of excisional and incisional biopsies. The results have been very satisfactory.

I started with simple cases of corns and warts. Once I was convinced with all the reports, I started expanding this application to moles and skin tags. Over the next 1 to 2 years, I used it for diagnosing clinical dermatologic conditions like psoriasis and lichen planus with very satisfactory results.

Using it for elevated dermatologic conditions was easier. I then decided to use it on flat lesions like unexplained hypopigmented or hyperpigmented macules and was convinced that I could reach the depth of the lower dermis while excising the biopsy piece from such macules in a single perfect stroke.

The next step was to use it to diagnose cases of leprosy, which is very common in India. This worked out very well. Since then, I have been using it for all cases of doubtful and frank leprosy with very good results. It was possible to get the proper classification of leprosy as well as tuberculoid or lepromatous and its subtypes.

The next step was to try it on blistering or vesiculobullous disorders. This was a challenging task, as to take biopsy for these disorders required making a cut deep enough to excise the recent vesicle in toto from its base and taking it without bursting. Conditions like pemphigus vulgaris, which have very superficial and flaccid bullae, was tough. Here and in macular lesions, the advantage was of using a larger size round loop electrode to reach beyond the base of the bullae into adjacent skin and to reach deeper dermis.

Finally, I decided to use it to diagnose cases of malignancy and basal cell carcinoma. Here, the cut needs to be sufficiently deep and wide as well to involve adjacent normal skin.

Vascular lesions like capillary hemangiomas and pyogenic granulomas were effectively excised for biopsy as well.

This is how radiofrequency surgery was incorporated in my practice as a diagnostic tool. I have always used the cut or fully filtered waveform at a power of 3 to 6. I prefer the round loop, straight needle, or thin wire electrodes, though one can always use the electrode of their choice (except for the broad needle electrode).

I have provided clinical photographs of lesions taken for biopsy and a range of histopathology photomicrographs for your perusal (Figures 16.1 to 16.14).